Cooling system



Jung 8, 1937. 5 DE BOTHEZAT 2,083,436

COOLING SYSTEM Filed Aug. 8, 1931 INVENTOR Patented June 8, 1937' UNITED STATES PATENT OFFICE 7 Claims.

This invention relates to cooling systems and particularly to the cooling of a liquid such as water.

The object of the invention is to provide a supply of liquid cooled by evaporation of a portion of the liquid and without the use of compressors and the like.

A further object of the invention is to provide a compact and efficient cooling means in which there is evaporation at substantially constant pressure from a liquid surface that is very large in comparison with the volume of the liquid to v be cooled.

In the accompanying drawing illustrating the invention.

Fig. 1 is an elevational view of a radiator adapted for use in the system of this invention,

Fig. 2 is a horizontal cross sectional view across the tubes of the radiator shown in Fig. 1.

Fig. 3 is a diagrammatic view of one embodiment of the system, and

Fig; 4' is a similar view illustrating a modiflca tion. In the embodiment of the invention shown in the drawing the radiator R has its tubes 8 formed in whole or in part of a porous material such as porous hygroscopic clay or porcelain or the like,

permitting aliquid such as water to seep through at suflicient rate to maintain the outer surfaces 0 of the tubes wet with a constant'supply of water. Preferably these tube walls are very thin, a few millimeters in thickness, and with the inside surfaces of the side walls spaced only a few millimeters apart. The thickness of the walls may be varied for instance with different materials and in different sizes of radiators for structural reasons, but these walls shouldbe maintained thin for the eflicient supply of moisture to the surface and the conductionof heat to the outside of the tube. The spacing of the inner walls and the cross section of the tube bore may also be varied, the closer spacing and smaller bore giving a desir able large surface area in proportion to the volume of the liquid being cooled. As shown in Fig. 2 the tubes may be stream line in cross section or they may be of any other desired form, such as elliptical or'circular, the stream line being preferred because of the lessened resistance to the passing of the evaporating cooling air stream. The water to be cooled enters the radiator R at the inlet 5 and the cooled water passes out by discharge 6. The radiator R is preferably set in a conduit or tunnel 1 as shown, and means is provided such as a fan F to force air through the radiator at'desired velocity, the speed of the fan being controllable for this purpose. A heating means H is provided either in advance of the fan as shown or between the fan and radiator, if preferred, and the supply of energy to the heater H is accurately controllable to regulate the heat- \5 ing of the air stream.

. The fan F is preferably of the disk type and the heater H comprises elements heated by any industrial means, such as gas, steam, electricity, etc., these elements being preferably so formed as 10 to provide large spaces ofiering little resistance to the flow of the air. The amount of heat to be added to the air will depend mainly upon the temperature and moisture content of the air as it enters the system, and in some cases no heating 15 of the air will be desirable. The fan F sucks the air through the heating coil H and blows it on the refrigerating radiator R. This produces an evaporation of the water on the surfaces of the refrigerating radiator and consequently causes a 20 cooling of the water in the radiator tubes. The

preheating of the air increases the drying ability (or evaporating ability) v0f the air and it is particularly desirable when the degree of humidity square meter of radiating surface for every kilo-'- 35 gram of water in its tubes 8, the thickness of the water layers in the tubes will be about 2 millimeters. To evaporate in one second 1% of 1 kilogram it will be sufiicient to evaporate from the radiating surface a layer of water only 0.01 milli- 40 meter in thickness, an extremely thin layer of water. 'Assuming that the air blowing on the. refrigerating radiator is at a temperature of 35 C. (308 absolute temperature) and humidity, and if the air is heated from 35 to 50 and again 45 saturates to 90% humidity when passing through the radiator, it can be shown that the air behind the radiator will then contain about 74 grams of water vapor per cubic meter of air, and since this air contains about 36 grams of water before en- 50 tering the radiator, .it is carrying away about 38 grams of water corresponding to a drop of temperature of the water of about 19 C. The actual cooling of the water will, of course, be less than this theoretical amount. 55

65 I -outside atmosphere. Phrinstance as shown in .By thus forming the radiating tubes of a material, such as porous hygroscopic clay or the like, water circulating through said tubes will seep through the surface to be cooled by air passing 5 over said surfaces'and the circulating .water withent mainly upon the difference in temperatures between the two irrespective of the velocity of the air as it passes, butthe cooling effect by evaporation depends essentially upon the speed of the air through the radiator, and by properly increasing the velocity of air flow the cooling byevap'oration can always be made to greatly exceed any heating effect. For every degree of humidity of the air there will be a best temperature to which the air should be .heated and a minimum air velocity through the radiator at which the most efllcient cooling will be obtained. It follows that a 'very'energetic emcient cooling '25 of the water can be obtained if water flowing through a coolingpassage, such as a radiator tube '0, is allowed to seep through the material of the tube to wet the surface thereof while at the same time a stream of air of proper humidity is blown over the wetted surfaces, the size and length of the tubes and the velocity .of the water therethrough being properly related to the speed and temperature of the air through the radiate and the degree of humidity of this air. a

This process dispenses with the use of compressors and can be used to replace the cooling tower process; and where only slight cooling of the water is required a preheating of the air can be omitted. The cooled water produced can be 40 used for the air conditioning of homes, buildings,

theatres, etc., and in such installations the procone would be used in connection with an air washer l I in whicha second fan ill (Fig. 3) circulates the ventilating air through the air washer II and delivers this cooled air through the baffles I! to the spaces to be cooled. The water cooling and air cooling means may be positioned as shown receiving air at one end and discharging it at the other, and the water from the air washer may be recirculated through the refrigerating radiatorR.

Other liquids than water may be cooled by this process, for instance, more easily evaporating liquids, so'as to decrease the dimensions of the apparatus and the amount of air to be circulated through the radiator R. With liquids of. lower freeaing temperatures lower temperatures can be obtained, and the liquid used can always be reerating radiator.

The air after it passes through the radiator R may be discharged or utilized in any desired manner, or may have its moisture content recondensed so as to control the humidity before it is passed onto other, spaces or discharged into the Fig. 4, this air from theradiator R could be passed through condenser tubes it around which cooler air is circulated by a fan It, the final mist or droplets .being separated out by banks of baiiles II." If desired, the air thus discharged from the condenser II can be returned again to the system, and thus used over and over again in the refrig erating circuit. Such an arrangemen be condensed from the-air and reused in the refrigspecially desirable when poisonous or otherwise objectionable vaporswould be involved.

Similarly the cooled liquid from the radiator R may be discharged directly into a cooling radiator or other container, andsuch ,a system would be particularly necessary when the liquid involves unpleasant or dangerous vapors.

This cooling process may be subjected to auto matic control as when a constant temperature of the liquid coming out of the radiator is desired or constant temperature 10f air passing through the air washer; The amount of preheating at heater K may be made dependent upon the degree of humidity of the air and the amount of air passing through the radiator, which depends upon the speed of the fan, or the adjustment of louvers, if such are used, may be controlled by the temperature of the liquid coming out of the radiator orthe temperature of the air coming out of the air washer in which the refrigerated liquid is used. 1

v For instance,-as' illustrated diagrammatically in Fig. 4, the supply to heater H may be varied by valve 20 controlled by the conventional hygrometer 22 in the entering air. The speed ofthe fan may as illustrated in Fig. 3 be, regulated as by a rheostat controlled through circuit 26 from the thermostat 21 in the discharged air. Similarly, as indicated in Pig. 4, the fan rheostat may be controlled through circuit 2' from thermostat II in the cooled liquid. discharged from the radiator.

I claim: 1

l. A cooling system consisting of'a refrigerating radiator with tubes having walls of porous hygroscopic clay or porcelain through which water is circulated and adapted to permit the water to seep to the exposed surface of the tubes, means for producing a current of air through said radiator, and means for preheating advance of the radiator automatically controlled by the degree of humidity of theair, the cooling of the water inside the radiator being obtained by evaporation onthe surface of the radiator tubes.

and means-for producing a current 0! air said radiator automatically controlled by the temperature of the cooled liquid discharged from the radiator.

a. A cooling system consisting or; nil-13cm ing radiator with tubes having walls of porous hygroscopic clay or porcelainthrough which water is circulated and adapted to permit the water to seep to the exposed surface of thetubes, and means for. producing a current of air-through said radiator automatically controlled by the temperature of the cooled liquid discharged'from the radiator, and means for the air. in advance of the radiator cimtrolled in accordance with the degree of humidity of the air.

4. Acooling system comprisingasourceofair,.

means for. giving the air a predetermined hmnidfor supplying a liquid to the opposite sides of said-tubes withinthe radiator, said uibes being porous-so as to provide outlets subjecting a portion of said liquid to the action of said air end supply using said liquid to cool the air supstream in said radiator so as to cool the remainder of the liquid therein.

5. A cooling system consisting of a refrigerating radiator with a number or closely spaced tubes having walls of porous material through which a liquid is adapted to seep and means for producing an air current over the exposed surfaces of said tubes comprising automatic means for controlling said air current according to the temperature of the air alter it has passed said tubes, the cooling of the liquid inside the radiator being obtained by evaporation on the exposed surface of the radiator tubes.

6. The combination with spaces to be ventilated, of an air conditioning system therefor comprising a plurality of separated air supply means leading to said spaces, means employing the first air supply to cool a liquid, means in the secply, andmeans for simultaneously furnishing air to said spaces through said air supplies in par-.

allel, receiving air at one end and discharging it at the other.

'7. The combination with spaces to be ventisupply, and means for simultaneously furnishing air to said spaces through said air supplies in parallel, receiving air at one end and discharging it at the other, the cooling means of the sec- 0nd supply system acting to spray liquid in the air stream.

, GEORGE na- BOTHEZAT. 

